I was not familiar with keyboard layouts including DEGREE SIGN handily, so I though there was at least a decent chance you had deliberately gone fancy. (I double-checked that it was ° and not º U+00BA MASCULINE ORDINAL INDICATOR, which I would expect to see on some keyboards, and “Nº” is incidentally distinctly better than “N°”, since it’s the shape of an o rather than a circle.)

To the best of my knowledge, I have never come across “n°” before. “№” plenty, “#” plenty, “No. ” plenty, “no. ” a few times, but not “n°” with a lowercase n.

Looking through <https://en.wikipedia.org/wiki/Numero_sign#Usages>… hmm, French AZERTY? I see now that it does have ° readily accessible.

I think another aspect that made it harder for me to recognise immediately was the lack of a full stop; I’d probably have recognised “n° 1” a bit faster. (I’d write “№ 1” rather than “№1”, though personally I’d go fancy with NARROW NO-BREAK SPACE, but that’s ’cos I enjoy doing crazy things like that.)

P.S. I live in Australia. Similar Anglocentrism to the USA in language, though less pronounced in matters of culture.